If the purpose of the if statement is to check for null or undefined values before assigning a value to a variable, you can make use of the Nullish Coalescing Operator.

May 10, 2013 · When declaring variables at the top of the JavaScript function, is it best practice to set them equal to null, or leave as 'undefined'? Another way to ask, what circumstances call …

Jan 4, 2024 · To check for null SPECIFICALLY you would use this: This test will ONLY pass for null and will not pass for "", undefined, false, 0, or NaN. Additionally, I've provided absolute …

May 7, 2023 · In this article, we will explore the standards and best practices for checking for these types of variables in JavaScript. Null: A variable that is null has been explicitly set to …

Apr 27, 2025 · The value null is written with a literal: null. null is not an identifier for a property of the global object, like undefined can be. Instead, null expresses a lack of identification, …

Jun 5, 2024 · In JavaScript, `null` indicates the deliberate absence of any object value. It's a primitive value that denotes the absence of a value or serves as a placeholder for an object …

Feb 23, 2025 · In JavaScript, handling null, undefined, and empty values is critical for building robust applications. These values represent different states of “nothingness” and can lead to …

Nov 29, 2022 · A variable has the type of null if it intentionally contains the value of null. In contrast, a variable has the type of undefined when you declare it without initiating a value.

Aug 28, 2024 · By this operator, we will learn how to check for null values in JavaScript by the (===) operator. This operator only passes for null values, not for undefined, false, 0, NaN.

Dec 4, 2016 · The standard way to catch null and undefined simultaneously is this: if (variable == null) { // do something } --which is 100% equivalent to the more explicit but less concise: if …